Piston-rod packing



" R. SHB'ARER. A Piston-Rod Packing.

. No. 225,558. Patented April 13, 1880.-.-

)L PETERS. PH'TC-LITHOGRAPHER. WASHIN'YON, U, C.

UNITED STATES PATENT OErIcEa ROBERT SHEARER, OF NEW ALBANY, INDIANA.

PlsToN-Roo PACKING.

SPECIFICATION forming part of Letters Patent No. 226,558, dated April 13, 1880.

Application filed September 13, 1879.

To all whom it may concern Be it known that I, ROBERT SHEARER, of New Albany, Floyd county, Indiana, have invented a new and useful Improvement in Piston-Rod Packing, of which the following is a specification.

My device is designed to be employed as auxiliary to the customary packing of cotton, hemp, or tow confined within the accustomed stuffing-box by means of the ordinary tight-I ening or compacting gland; and my device consists of a wad or backing of india-rubber, formed from a bar or strip of that material, whose transverse section is a right-angled triangle. This bar is bent into the shape of a circular ring having its bevel face presented inward, to occupy the back corner of the stuffing-box, and when thus placed to cooperate with the gland to force or wedge the tow or other packing more closely against the piston-rod or other sliding rod with which it is designed to operate. \Vhen thus associated the elasticity of the funnel-formed backing becomes auxiliary to that of the packing proper to maintain an equable and enduring pressure upon the rod, and thus prevent leaka e.

gThe metallic facing protects the rubber from i wear, and also enables the packing proper to slip more easily rearward under the glandpressure than it would do it directly in contact'with the rubber itself.

For the material of my backing I employ vulcanized rubber, such as customarily used by engine-builders, and preferably form it, in suitable' molds or matrices, in long strips of the proper triangular section, which are afterward ont into lengths to flt the specific boxes.

In the accompanying drawings, Figure l is an axial section of a stufng-box provided with my invention. Fig. 2 is a transverse section of the same at the line sv Figs. 3 and 4 are, respectively, detached views of my rubber backing-strip and my sheet-metal facingplate.

A may represent a portion of a cylinderhead; B, customary stuffing-box; G, customary gland; D its tightening-bolts; E, pistonrod.

F represents my rubber backing having the represented triangular section, enabling it to lit and occupy the rear angle of the box, as shown in Fig. 1.

G is a piece of thin sheet-copper or other sheet metal, cut to the proper shape to lit the hollow conical surface of the inserted backing, and having its exposed surface smooth or polished in order that the packing proper, H, may slide easily rearward in obedience to the pressure of the compacting-gland.

While the surface presented to the packing properis sufficiently iirm to maintain the funnel shape necessary to produce the desired crowding action upon the packing, the backing and its thin metallic facing-plate are, at the same time, sufliciently elastic to aid the elasticity of the packing proper in preserving a substantially-uniform pressure upon all parts of the rod brought in contact with said packing proper.

The essential feature of my improvement is the funnel-formed rubber backing employed with a smooth-and llexible metallic facing for use with any ordinary or suitable stuffing-box gland and means of tightening the latter.

I am aware that it has been proposed to use for the packing proper an annular roll of canvas saturated with india-rubber, such roll to be seated upon a conical, but necessarily inelastic, slope of the box-wall. I therefore disclaim novelty in the use of rubber, except in the mode and manner employed by me-namely, not as the packing proper, but as an elastic backing to the ordinary cotton, hemp, or other customary or suitable packing material employed.

I am also aware that it has been proposed to employ sheet-metal lining for stuffing-box packing, but always, so far as known to me, for direct contact with the rod, and not for a portion of the backing, as in my improvement. v

I claim as new and of my invention- As a new article of manufacture, the described funnel-formed backin g-rin g F, of indiarubber, having thin metal facing G, inclosing the soft packing proper, H, and associated with the box B, gland (l, and compressing means D, substantially as and for the purpose set forth.

In testimony of which invention I hereunto set my hand.

ROBERT SHEARER.

Attest: y

GEO. H. KNIGHT, JAs. V. KELso.

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